JPH02154247A - Original still picture reader - Google Patents

Abstract

PURPOSE:To prevent deterioration in a read-out picture caused by the defocus of a rod lens array by pressing travel roller which travel in the subscan direction with respect to a carrier and two shafts, which slidably support the carrier, against an original glass plate. CONSTITUTION:Since a shaft 8 is supported by push rods 26 pressed with a press spring 25 and is pushed upward, the travel roller 21 on a plate 20 which is placed on the carrier 4 supported by the shaft 8 receives the repulsive force of the press spring 25 to come into contact with the original glass plate 5. Because the push rods 26 which press both ends of the shaft 8 in the upward direction are independently operated, all the four travel rollers 21 come into contact with the original glass plate 5. Therefore, when the original glass plate 5 is deformed by weight of an original such as a thick book or by the press- force of an operator's hands, the travel roller 21 can constantly travel in contact with the original glass plate 5. Thereby, the deterioration in a read-out picture can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a static document image reading device, in particular, to a device for displacing a part of an optical system according to the deformation of a document surface glass in order to improve the quality of the read image. The present invention relates to a still document image reading device.

[Conventional technology]

FIG. 7 is a perspective view of a main part showing the structure of a conventional document static image reading device disclosed in, for example, Japanese Unexamined Patent Publication No. 60-260915, and FIG. 8 is an enlarged sectional view of the reading portion of the device. In the figure, 1 is a rod lens array, 2 is a light source provided on both sides of this rod lens array 10, 3 is a photoelectric conversion element provided below this rod lens array 1,
4 is the rod lens array 1. Light source 2. This is a carrier on which photoelectric conversion elements 3 are loaded. Reference numeral 5 denotes a document surface glass, which is attached to the main body 6 of the apparatus at a constant distance from the rod lens array 1. Reference numeral 7 designates a sliding bearing provided at one end of the carrier 4, which is slidably attached to a shaft 8 fixed to the main body 6 of the device in parallel with the document surface glass 5, so that the carrier 4 can be positioned in the main scanning direction. and supported so as to be movable in the sub-scanning direction. A wheel 9 is rotatably attached to the other end of the carrier 4, and the carrier 4 is positioned in the vertical direction by a rail 10 fixed to the apparatus main body 6 in parallel with the document surface glass 5. Reference numeral 11 denotes an electric circuit section, which includes a circuit for driving the photoelectric conversion element 3 and the like, and is fixed to the carrier 4. Reference numeral 12 denotes a stepping motor, which is fixed to the main body 6 of the apparatus by a mounting stay 13.

A pulley 14a is attached to the shaft of the motor 12, and a pulley 14b tensions the belt 15.

A portion of the belt 15 is fixed to the carrier 4. 1
Reference numeral 6 denotes a document, which is placed on document surface glass 5 with the surface to be read facing the glass when reading an image. 1γ is a fluorescent lamp inverter, which supplies power to the light source 2 through a flat cable 18. A flat cable 19 transmits the image signal from the photoelectric conversion element 3 to the outside.

Next, the operation will be explained. When reading an image, the power of the inverter 17 is transferred to the flat cable 18 according to an external instruction.
The light is transmitted to the light source 2 through the light source 2, and the light source 2 is turned on to illuminate the document 16 on the document surface glass 5. The reflected light from the original 16 is imaged at the same magnification by the rod lens array 1 onto the photoelectric conversion element 3 .

The photoelectric conversion element 3 is driven by a drive circuit (not particularly shown) in the electric circuit section 11, and sequentially converts into an electric signal in the main scanning direction. By simultaneously rotating the stepping motor 12, its power is transmitted to the carrier 4 via the pulleys 14a, 14b and the belt 15. , and the carrier 4 moves in the sub-scanning direction.

Further, one end of the carrier 4 is supported by a wheel 9 and a rail 10, and a shaft 8. Since the rail 10 is fixed parallel to the original glass 5, the carrier 4 always moves at a constant distance from the original 16 on the original glass 5. By sequentially and electrically reading the carrier 4 in the main scanning direction while mechanically moving the carrier 4 in the sub-scanning direction, the image (not shown) of the document 16 is converted into an electrical signal, and the image is transmitted through the flat cable 19. , and send it to the outside as a read image signal.

[Problem to be solved by the invention]

Since the conventional document static image reading device is constructed as described above, the document surface glass 5 is exposed to the weight of the document such as a thick book and the pressure exerted by the operator's hand.
This causes problems such as the reflected light from the original 16 not being correctly focused on the photoelectric conversion element 3, resulting in deterioration of the quality of the read image.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a stationary original image reading device in which a carrier loaded with photoelectric conversion elements can move while always maintaining a constant distance from the original glass. With the goal.

[Means to solve the problem]

In the document static image reading device according to the present invention, a traveling roller that runs in the sub-scanning direction is attached to the carrier so as to be in contact with the document surface glass, and a shaft that slidably supports the carrier is attached to the document by a shaft support device. It has a structure that allows it to be pressed elastically toward the surface glass.

[For production]

The carrier in this invention is pressed against the original glass side by a shaft that is pressed toward the original glass, and the carrier runs while the traveling roller provided on the carrier and the original glass are in contact with each other, so that the carrier is always in contact with the original glass. This works by keeping the optical system including the photoelectric conversion element at the same distance.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a rod lens array, 2 is a light source provided near the rod lens array 1, 3 is a photoelectric conversion element provided below the rod lens array 1, and 4 is the rod lens array 1 and the light source 2. , a carrier on which the photoelectric conversion element 3 is loaded, and these are shown enlarged in FIG. 20 is a plate attached to both sides (front and back) of the carrier 4, 21 is a running roller attached to the upper part of each plate 20, 5 is a document surface glass supported by these running rollers 221, and 6a is a The device top plate of the main device 6, 6b is the device side plate, 6c is the device bottom plate, and T is the sliding bearing provided on the carrier 4. Further, in FIG. 3, which is a side view of FIG. 2, 22 is a sliding plate provided at the other end of the carrier 4, and 8 is a shaft. It is slidably supported on the shaft 8 by a moving plate 22. 12 is a steering motor, which is fixed to the bottom plate 6C of the apparatus. 1
4a is a pulley attached to the shaft of the stepping motor 12, 14b is a deceleration pulley, and 15a is a deceleration belt stretched between the pulley 14a and the deceleration pulley 14b. 1
4C is a pulley that is coaxial with the reduction boob IJ 14 b and is rotatably installed on the bottom plate 6C of the device, 14 d is a pulley that is rotatably installed on the bottom plate 6C of the device, and 15b is the pulley IJ 14 C and the boo IJ 14 d. A part of the belt is stretched between the carriers 4 and 4, and a portion of the belt is fixed to the carrier 4 by a fixing member (not shown). Further, in FIG. 4, reference numeral 23 denotes a bracket, which is positioned on each device side plate 6b and fixed with screws 27 as shown in FIG. 6. The bracket 23 has a long hole 2 extending vertically.
3a, the minor diameter of which is equal to the outer diameter of the shaft 8, and the shaft 8 is positioned in the main scanning direction by being fitted into the elongated holes 23a of the pair of brackets 23. Reference numeral 24 denotes a spring holder, which is screwed and fixed below the shaft 8 onto the device bottom plate 6C together with the device side plate 6b. The details of this are as shown in FIGS. 4 and 5, and 25 is a suppressing spring, which is installed in the spring holder 240 cylinder. A bushing rod 26 is fitted into the spring holder 24, supported by the pressing spring 25, and further presses the shaft 8 upward. Note that a notch 26a for receiving and holding the shaft 8 is provided at the upper end of the bushing rod 26. And these spring holders 2
4. The suppression spring 25 and bushing rod 26 constitute a shaft support device 28.

Next, the operation will be explained. The operation during image reading is similar to the conventional example. In this invention, the shaft 8 is supported by the push rod 26 pressed by the suppression spring 25 and is pushed upward, so that the plate 8 installed on the carrier 4 supported by the shaft 8 as shown in FIG. The running low 221 on 20 is the pressing spring 2
50 and comes into contact with the document surface glass 5. The push rod 26 that presses both ends of the shirt h8 upward is
Since each operates independently, the four running rollers 21
all come into contact with the document surface glass 5.

Therefore, even if the document surface glass 5 is deformed due to the weight of the document such as a thick book or the pressing force of the operator's hand, the running roller 21 always travels in contact with the document surface glass 5. Therefore, the carrier 4 is also displaced according to the deformation, and the rod lens array 1 and photoelectric conversion element 3 loaded on the carrier 4 always travel while maintaining a constant distance from the document surface glass 5. Further, the elongated hole 23a provided in the bracket 23 for positioning the shaft 8 is made vertical when the device side plate 6b is attached, and its short axis is the shaft 8.
The shaft 8 positioned by the pair of brackets 23 does not move in the main scanning direction, but can freely move in the vertical direction. Therefore, the carrier 4 moves only in the vertical direction in accordance with the deformation of the document surface glass 5, and does not move in the main scanning direction. In addition, since the carrier 4 is interposed between the shaft 8 and the original glass 5 by a pressing member 25, the accuracy of assembling the shaft 8 and the original glass 5 during assembly of the apparatus is poor. Also, the carrier 4 and the original glass 5 always maintain a constant distance.As a result, deterioration of the read image due to defocus of the rod lens array 1 does not occur.

In the above embodiment, one pair of brackets 23 are used for positioning the shaft 8, but a similar elongated hole for positioning the shaft 8 may be provided in the device side plate 6b itself (as in the above embodiment). It has the same effect as.

Further, in the above embodiment, a coil spring is used as the pressing spring 25 that presses the bushing rod 26 upward, but a spring such as a leaf or a toshicon bar, or an elastic material such as rubber may also be used. It has the same effect as the example.

Further, in the above embodiment, the pressing force of the suppression spring 25 is transmitted to the shaft 8 via the bushing rod 26, but a structure may be adopted in which the suppression spring 25 directly presses the shaft 8.

In addition, the running roller 21 is connected to the plates 2 on both end surfaces of the carrier 4.
0, but the carrier 4 may be rotatably supported directly on both end surfaces of the carrier 4.

Furthermore, although four running rollers 21 are shown, two in each main scanning direction of the carrier 4, a plurality of rollers other than four may be used.

〔Effect of the invention〕

As described above, according to the present invention, the running roller that runs in the sub-scanning direction is attached to the carrier so as to be in contact with the document surface glass, and the two shafts that slidably support the carrier are connected to the pressing member. Since the structure is configured so that the photoelectric conversion element on the carrier is pressed toward the document surface glass, the carrier can be smoothly fed in sub-scanning while always keeping a constant distance between the photoelectric conversion element on the carrier and the document surface glass. In addition to preventing deterioration of the read image due to defocusing of the image, it is also possible to eliminate the need for vertical positioning of the shaft and document surface glass when assembling the device.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view showing the entirety of a still document image reading device according to an embodiment of the present invention, FIG. 2 is a front cross-sectional view showing an enlarged view of the carrier shown in FIG. 1, and FIG. 1 is a side sectional view showing the carrier, FIG. 4 is an enlarged front sectional view showing the shaft support structure shown in FIG. 1, and FIG. 5 is a main view showing the shaft support structure shown in FIG. 1. FIG. 6 is a side view of the main part showing the fitted state of the shaft and bracket shown in FIG. 1, and FIG. 7 is a perspective view of the main part showing the conventional document static image reading device. , FIG. 8 is a front sectional view showing the optical system of the apparatus shown in FIG. 7. 1 is a rod lens array, 3 is a photoelectric conversion element, 4 is a carrier, 5 is a document surface glass, 8 is a shaft, 21 is a running roller, and 28 is a shaft support device. In addition, the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A document surface glass on which a document is placed, a rod lens array that receives reflected light from the document and forms an image on a photoelectric conversion element, and a sub-scanning device that holds this rod lens array and maintains it parallel to the document surface glass. A stationary original image reading device comprising: a carrier that moves in the sub-scanning direction; What is claimed is: 1. A stationary document image reading device comprising: a shaft supported slidably in a direction; and a shaft support device elastically pressing the shaft toward a document surface glass.